This invention relates to a magazine for holding a stack of cutting means elements. More specifically, the present invention relates to a cutting means magazine for use in an apparatus for forming a sterile connection (sterile docking) between two tubes.
U.S. patent application Ser. No. 267,291, filed on June 4, 1981 now U.S. Pat. No. 4,369,779, discloses an apparatus for forming a sterile connection comprising a cutting means, means adapted to heat said cutting means, a pair of mounting blocks adapted to receive and hold two tubes to be joined, means to provide movement between said blocks and said cutting means to a position such that the cutting means is between said blocks and traversing where the blocks are adapted to receive tubes, means adapted to realign said blocks to a position where two different tube ends are aligned with and facing each other, and means to separate said blocks and said cutting means while urging said blocks together. The application discloses that the cutting means can take many forms, can have the shape of a knife, can be either permanent or disposable, and can be a composite made according to printed circuit technology in single blades or blades mounted in a magazine.
During the further development of the aforesaid sterile docking device having incorporated therein a cutting means magazine it was found that during feeding occasionally two cutting means were fed instead of one causing jamming in the exit slot and that sometimes the feeder arm or ejector would miss or lose its grip on the cutting means resulting in no cutting means being advanced into the cutting means holder. In the first situation, no cutting means is advanced even though the ejection arm completes its forward stroke and indicates a fresh cutting means is in proper position. Thus, the next sterile docking operation would then be tried with an old cutting means. In the second situation, a fresh cutting means may be advanced only part way even though the ejection arm completes its forward stroke and indicates that a fresh cutting means is in proper position. If a sterile docking operation were attempted with the apparatus in this situation, the docking mechanism would jam on the partially advanced cutting means. Thus, there exists a need for an improved cutting means magazine which would minimize the foregoing problems.
Various blade magazines have been disclosed in the art. U.S. Pat. No. 1,737,696 issued to Allen on Dec. 3, 1929 discloses a blade holding magazine to be used in combination with a razor blade, said magazine comprising a rectangular chamber in which blades are held, a cover closing the chamber, a spring to press the blades toward the cover, and a push bar or blade feeding member slidably mounted in the magazine directly under the cover and capable of being reciprocated to discharge blades from the magazine. U.S. Pat. No. 2,676,396 issued to Testi on Apr. 27, 1954 discloses a combination of a safety razor and a blade magazine. The magazine includes in its structure an elongated rectangular shell having a bottom, sides and top flanges which extend inwardly toward each other but are separated by a substantially open space. One end of the magazine is open for reception of the razor head and the other end has a rear wall formed by a base plate. The magazine is provided with a feed slide having side flanges which engage the walls of the shell and an inner blade engaging plate which is connected to the slide by a stud. A bowed spring is used to maintain the stack of blades in contact with the top flanges.
U.S. Pat. No. 2,680,291 issued to Shnitzler et al. on June 8, 1954 discloses a blade magazine comprising an elongated channel shaped plastic casing with parallel side walls having opposed grooves and end walls, one of the end walls being recessed at an upper corner, one side wall having an open cut-away portion at its end opposite to the recessed end wall, and a sheet metal cover fitting at its edges in said grooves and having at one end an ear bent into the recess of said end wall and at the other end an angular section bent into the open cut-away portion in the side wall of the casing, thus positively holding the cover against longitudinal displacement in either direction on the casing. The magazine has a bowed spring for holding the uppermost blade in contact with the inner face of the cover and the front end wall of the casing terminates slightly below the opposed grooves in the side walls of the casing and thus defines an exit slit at the end of the magazine. A feed slide is mounted to the cover of the magazine.
U.S. Pat. No. 2,718,963 issued to Austin on Sept. 27, 1955 discloses a razor blade magazine comprising a casing, a stack of single edged blades therein and a spring urging the stack against a wall of the casing, the casing having an exit slot aligned with the top blade of the stack to permit ejection thereof and a pusher slot for accommodating a blade ejector, the pusher slot extending diagonally across the top blade of the stack from a point adjacent a back corner of the blade near the exit slot to a point adjacent an edge corner of the blade near the opposite end of the casing. The blade ejector is external to the magazine.
Other patents which disclose blade magazines include U.S. Pat. No. 3,850,343 which specifies that the thickness of the blade pusher web is less than the thickness of a blade unit and U.S. Pat. Nos. 2,686,967, 2,697,276 and 2,812,576.